Method of making pig-iron from steel-scrap.



' should only exist in the form of combined UNITED STATES PATENT OFFICE.

HORACE W. LASH, 0F CLEVELAND, OHIO, ASSIGNOR TO THE VEST COAST IRON COM-PANY, OF SAN FRANCISCO, CALIFORNIA, A CORPORATION OF OHIO.

METHOD OF MAKING PIG-IRON FROM'STEEL-SCRAP.

No Drawing.

'1 b all whom it may concern:

Be it known that I, I'IORAUE \V. Imsu, a citizen of the United States,residing at Cleveland, in the. county of Guyahoga and State of Ohio,have invented certain new and useful Improvements in Methods of :MakinPig-Iron from Steel-Scrap,of which the fol owing is a specification.

Pig iron as commonly understood is the product of the blast furnace, andis produced directly from the iron ore with the aid of carbon andlimestone. This product of the blast furnace in its natural condition issuitable for the manufacture of iron castings, or by further well knowntreatment may be converted into Wrought iron or steel for commercialpurposes. Where the pig iron is converted into steel, the carbon andsilicon contained therein are practically eliminated, due to the factthat but little, if any, silicon is desired in the finished steel andthe carbon carbon and very rarely'exceeds one and onehalf per cent,although some grades of steel carry approximately two per cent. ofcarbon. However, such is the extreme limit, and any thing beyond this,especiallywhere graphitie carbon and silicon exists to any extent, Wouldcome under the head of cast or pig irozn So far as I am aware all pigiron heretofore manufactured has been roduced in the main from the ironore. and approximately one hundred tons OI the ore is required toproduce fifty tons of pig iron. here the fuel employed, such as coke, isplentiful pig iron may be produced from the ore at comparatively areasonable cost, but in places where the usual fuel employed isextremely expensive, the cost incident to the production of the pig ironis substantially prohibitive to the manufacture thereof, even should aplentiful supply of the ore exist in such territory. On the Pacificslope ani'lmore ,45 particularly in the States of California. the

gon and Washington, the cost of coke or other fuel ordinarily employedin the red action of iron ore is too expensiveto permit of theemployment thereof for the economic production of pig iron, inasmuch asthe cost of the finished article would greatly exceed that for which thesame ma y be purchased elsewhere and brought into such territory.

The object of the present invention is to produce pig iron within theState of California, or other territory having an ample Specification ofLetters Patent.

Application filed March 2, 1912.

Patented May 6, 191.3.

Serial No. 681,286.

supply of low cost fuel, at a price substantially that at which the samemay he manufactured in more favored territory as to fuel and ore, say,at Pittsburgh, PClllL, taking said district as controlling the cost ofproduction and Where pig iron may no produced this commodity in theStates of California, I

Oregon and lVashington during the past ten years has ranged from twentyto thirtytwo dollars per ton.

In California there is a large supply of cheap fuel in the form of oilwhich may be utilized for the production of pig iron, and while in theStates of California, Oregon and \Vashington, theconsumption of pig ironis about one hundred thousand tons annually, there is annually producedin said States approximately two hundred thousand tons of scrap materialconsisting largely of steel, although therc"is contained within saidscrap material a small per cent. of wrought iron and cast iron, and bythe expression scrap material as hereinafter employed is meant discardedsteel, or a mixture of steel and wrought iron, also a mixture of. steel,wrought iron and cast iron. the scrap steel however predominating. Thismaterial oompriscs old rails, girders, beams, sheets, turnings, bars.borings, etc., in the main discarded and worn out material from therailroads. manufacturing and surplus material from fabricating plants.It is this discarded material having but small value, limited market andthe selling price of which on the Pacific coast ranges between three andeight dollars per ton, that I have discovered may be successfullyutilized for the production of pig iron on the Pacific coast at a costof approximately thirteen dollars per ton, which issubstantially thecost per ten for the manufacture of the pig iron at Pittsburgh, Penn,and by so doing enabling pig iron to be sold on the Pacific coast at a.price per ton substantially equal to the selling price per ton atPittsburgh, Penn, While 7 at the same time not only creating a newindustry for the Pacific slope, but enabling a low value commodity to beconverted into a product having an enhanced value and in-- creasedselling price. From every one hundred tons of the said scra materialslightly over one hundred tons o pig iron may be produced, whereas, asa'bove stated, under "utilized as the fuel medium.

The charge for the production of an average grade offoundr'y pigironwo'uld be about as follows scrap inate1-ia'l'8)%; iia'rb'dn.1'0%';ei1ie'a -10%; howev r, the amdunt of caiboh and silica present should beregulated by this meant of carbon and s'il'i'con'desired in the sharedproduct. During the 'ch'a'rgin nace, care should be used in placing tlreniaj or portion of the carbon in or n-ear the bottom of the furnacewhere it can b given pret'e'c tlion 'from 'theokidiz inlg name by -beingthoreuglfl covered with theserap portion"ofthe charge. During {themelting bit 'the charge mixture a part of the a rbdn is chemicall unitedwith the iron, and a p'ait is held in the rem of nee carbon orfiraphim,the excess carbon present eating as a reducing agent in the reduction ofthe Since edetaia'ea in the mixture to silicon, which l'atteralso uniteswith the 'ii'on and thereby farms "pig iron or ap roximately therenewproduct into pig iron ing chemical composition F Ca'rbon combined)1.00%- 7 Carbon (graphite) 2,59% Silicon 2. 00% Sulfur .1022; Phosphorus20% Iron 94:. 20%

In carrying out the process er converting the scrap material derivedfrom 'fi'nished" I from which it was originally produced, it is notessential. 'that the silicon be derived from the use ofsilic'a in thecharge mixture, inasmuch "as "the 'sa'ine may be provided "in "part orall by the use of "Elmo-silicon or by the addition bfa small quantity ofhighly'silidious pig area Hewever, -i'n-e1the'r case the result "wouldbe practically the saiile, but, fd'r economical 'rastiiis,

of the ih'i-X'ture into the furit is desirable to obtain the siliconfrom the silicaused in the mixture.

While any suitable type of melting furnace may be employed, preferenceis given to the use ofea reverberatory furnace, and the charge fedtherein is subjected to a melting heat suflic-ient to reduce the sameto-a fl'uid condition, and when the charge has been brought to theproper condition of fluidity, it is drawn ofi'in the usual mannera'ndcast into pigs or such other forms as may be desirai'le for thepurpose for which it is to be use viz. the production of pig iron by theconversion of the Waste material of a finished product into pig iron,and by 'so doing not only giving an increased value to the same, butpermitting pig i-ron to be produced and placed on the market in placeswhere the usual conditions for the manufanure thereo f do not preven andat a cost substantially the same as that which prevails in the igvdredplaces for the manufacture thereof. ere'tofo're, the mentioned scrapmaterial has simply been utilized by a re'meltir'rg and reworkingthereof, 2'. e.- to say the scrap marketable steel, but the material hasnot 1 been changed or converted into a difle'rent "product ormanufacture. It has simply riy the foregoing it new industry is created,

been a case of fusing together or re-uniting 7 the scrap pieces, but inno ma'nher has the character of the material been changed, in- I as'muohas in the case of scrap steel it comes out of "the factory plant assteel. In the present 'case the scrap material in the form of separateieces is re-melted and converted into a different product, viz.pigi'rfin I tto'r use in connection with the manufacture or iron castings,steel and wrought iron, or, in other words, "the waste material of afinished product is converted into that from which it was manufactured.Tn the one "case iron ore is employed as the base for the manufacture ofpig iron 'for the *duction of castings, steel and wrought iron,

whereas in the-present case the "mentib iied scrap material of afinished product is j utilized as the base for the manufacture of pigiron. "In the former case it is re uiredto treat approximately onehundred tons of a iron ore to produce substantially fifty tons of pigiron, Whereas in the latter case one hundred tons of scrap material withthe proper mixture of carbon and silica will produce slightly tons ofpig iron.

By the described method pig iron may be produced "in furnaces other thana blast more than one hundred furnace, and at a 'very low cost of f nianw. fl facture in distaste where 's'ra'p material as a described, fueloil and "da t-Hon use pleritiful,

and the manufacture thereof successfully compete With the production "ofpig 'ifdn under the methods at present employed in the most favoreddistricts.

The importance of the invention to manufacturers situated in territorieshaving an ample supply of scrap material, fuel oil and carbon butsituated at a remote distance from the favored localities for themanufacture of pig iron, will be readily apparent to those skilled inthe art and users of pig iron in large quantities.

The foregoing conditions for the manufacture of pi iron on thePacificcoast is rendered posslble due to the available supply of scrap materialand an .unl'imited supply of cheap fuel oil and carbon within the Stateof California, and itiscthese con ditions which have been takenadvantage of in carrying out the foregoing invent-ion.

While the proportion of the-charge mixture as before given is deemedbest for the production of an average grade of foundry iron, the samemay be varied asdesired without departing from the invention, theessential feature of which resides in the production of pig iron from abase consisti'ngof scrap material of the character hereinbeforementioned.

Having thus described the invention what,

is claimed as new and desired to be protected by Letters Patent is:

1. A method of making cast iron which consists in melting in areverberatm'y furnace, a mixture of steel scrap, carbon, and siliciousmaterial, the carbon of the charge being distributed in the chargemixture in a manner to be protected from the oxidizing flame of thefurnace.

2. A method of making cast iron which consists in meltin in areverberatory furnace, a mixture 0 steel scrap, carbon, and siliciousmaterial, the carbon effective for chemical re-action with the chargebeing placed within the charge mixture at or near the hearth of thefurnace, whereby it is protected from the oxidizing flame of thefurnace.

a In testimony whereof I have signed my name to this specification inthe presence of two subscribing witnesses.

HORACE W. LASH.

